i smoke 2 turkey legs

With turkey legs, always cook thoroughly...I think your 3 hours is in the ballpark. Always err on the overcook side as opposed to undercooking, they need the toughness cooked out of them.

I am now at 5 hr and temp is 160 will keep on a little while lomger

Well, I'm probably too late here...but mesquite is a little heavy on turkey legs, IMHO I woulda suggested cherry/apple and not a whole lot, though I know your control isn't great with the propane smoker. If it's not too late, I surely wouldn't add wood once it's gone.

I think the brining, still, will help with the leg, though not as dramatically as with a breast. I've done the same experiments with both turkey and chicken and though not completely necessary on the dark meat of either, it doesn't hurt ya much.

Oh, and...not to make you crazier...it's tough to get an accurate reading on the internal temp of a turkey leg....no big sections of meat to hit, and lots of other 'stuff' going on in there! So, instant read thermo in a few spots I'd suggest.

my first attemptwas ok. did them 5 hr ,used misquite . the one I brined was much jusier than the one I did not. Agreee to much smoke next time will use another wood. my next attempt will be a whole chicken (beer Butt) i figure 5-6 hr as it is a 5lb bird, will be sure to brine